The Cell and Immunology Core of the NIDA P30 Center provides the expertise and resources for researchers to expand their investigations to include immunological, cellular and histological endpoints. The capability of carrying out immune assays provides a fertile area for collaborations to investigate the potential role of chemokines and cytokines in addictive processes. Analyses can be performed on fluids, tissues, or homogenates obtained from rodents or humans. Many projects supported by the Cell and Immunology Core investigate the effects of the intersection of drugs with HIV infection in rodent models or in human tissue or blood samples. The Core has carried out projects relating to effects of a wide variety of abused substances including opioids, cannabinoids, psychostimulants, nicotine, and alcohol. The Cell and Immunology Core provides expertise in measurement of chemokines, cytokines, and hormones in plasma, homogenized brain or brain substructure tissues, brain dialysate fluid, spleen or lymph node homogenates, and cell culture supernatants using protein arrays, as well as multiplex platforms for simultaneously measuring a panel of mediators, and by ELISA for assay of levels of single immune mediators. The Core also offers a variety of histological and tissue imaging techniques for examining aspects of brain function including receptor expression, microglial activation, dendritic spine density, and blood-brain barrier integrity. Resources available include tissue processing, embedding, sectioning and detection using chromogens and fluorescence (single or multiplex). Advanced techniques offered include tissue clearing (via CLARITY) and special stains such Golgi-cox and Fluro-Jade staining. In addition, the Core offers epifluorescence, confocal, intravital and live cell microscopy. Image analysis for area, particle analysis, tracking and 3D volumetric measurements can be performed using dedicated workstations configured to run NIS elements AR (Nikon) and Imaris (Bitplane). The Core has available the in-situ hybridization platform from RNAscope to detect RNA in tissues. The Core also carries out functional immune assays such as the Mixed Lymphocyte Reaction (MLR), an in vitro correlate of organ and skin graft rejection, response of lymphocytes to mitogens, Natural Killer cell activity, and in vitro antibody formation. The Core screens cell lines for those doing research in substance abuse for mycoplasma contamination. The Core is committed to mentoring trainees and faculty new to immunological assays and imaging analysis by teaching them the theory behind various assays and instructing them in how to carry out the techniques.